1. Field of the Invention
The present invention relates to an electronic mail (hereinafter, referred to as E-mail) communication apparatus and, more specifically, to an E-mail communication apparatus which is capable of transmitting mails as an encrypted data.
2. Description of the Related Art
In the related art, there is provided an E-mail communication apparatus including public key transmitting means for transmitting a new public key of an apparatus to E-mail addresses stored in address information storage means in advance when the public key of the apparatus is newly registered or renewed for the reason of expiration or the like. Accordingly, the new public key is efficiently transmitted to destinations of communication.
However, even though a destination terminal has the above-described function, if the source address is not stored in the address information storage means of the destination terminal, a new public key is not transmitted from the destination terminal, and the source cannot receive the public key. Therefore, when transmitting the encrypted mail, there may be a case that an electronic certificate (including the public key) of the destination terminal cannot be acquired.